61 and 63, New Cavendish Street W1

Nos. 61 and 63 New Cavendish Street are a pair of terraced townhouses built between 1775 and 1777 as part of the Portland Estate development by John Johnson. No. 61 was fitted out for William Udny, while No. 63 was for Sir Charles Bampfylde. The houses are constructed of stock brick with a concealed slate roof and feature a generously proportioned, astylar elevation that presents a unified tripartite composition, closing the north vista of Mansfield Street designed by the Adam Brothers.

The buildings rise four storeys, with the top floor serving as an attic, and have basements. They are seven windows wide, with the central three bays slightly advanced. The central section includes semicircular arched doorways flanked by similarly arched windows, all recessed and adorned with Coade stone vermiculated rustications, fluted impost bands, head keystones, panelled doors, sidelights, and patterned fanlights. The windows have renewed glazing bar sashes set under flat gauged arches.

On the first floor, there is a continuous bracketed balcony with a Victorian scrollwork iron balustrade and a tent-roofed verandah, while the second floor windows feature tent hoods added at the same time as the verandah. The main stucco cornice is located above the second floor, with an attic cornice and blocking course. The properties also have plumbed spike area railings, with a surviving urn finialed standard to the right.

The interiors are notably fine, reflecting a style reminiscent of Wyatt, featuring geometrical stone staircases with delicate wrought iron balustrades, plasterwork friezes and ceilings with inset painted panels, arabesque, and "Etruscan" details. Notable rooms include an apse-ended library and a drawing room in No. 61 with a segmental vaulted and pendentive domed ceiling, as well as statuary marble chimneypieces.